1. Field of the Invention
The present invention relates to a developer container for use in an image forming apparatus and storing a developer to be replenished to the image forming apparatus.
2. Description of the Related Art
A predominant type of developing device for use in a copier, facsimile apparatus or similar electrophotographic image forming apparatus uses a two-ingredient type developer, i.e., a toner and carrier mixture. In this type of developing device, toner contained in the developer is consumed little by little due to repeated image formation, so that fresh toner must be replenished to the developing device at adequate timing. For this purpose, a toner bottle, toner cartridge or similar toner container packed with fresh toner is removably mounted to the image forming apparatus for replenishing the toner to the developing device.
To replenish toner from the toner container to the developing device, use has customarily been made of mechanical auger means that allows the amount of toner conveyance to be controlled. However, a problem with auger means is that it is applicable only to a substantially straight conveyance path. Another problem is that if the conveyance path is long, the quality of toner is lowered due to, e.g., cohesion. It is therefore necessary to locate the toner container in the vicinity of the developing device. Further, auger means cannot lift toner at an acute angle even if the conveyance path is short, so that the toner container must be positioned at a higher level than the developing device.
Japanese Patent Laid-Open Publication Nos. 2002-139902 and 2001-166581, for example, teach toner replenishing devices configured to solve the above problems. However, the devices taught in these documents have a drawback that a developer leaks when a toner container is removed after use and a drawback that much toner is left in the removed toner container.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Laid-Open Publication No. 2001-100506.